1. Field of the Invention
The present invention relates to an anti-corrosive coating composition precursor.
2. Description of the Related Art
In recent years, the use of polyaniline as a conductive resin for an anti-corrosive coating composition is studied.
The above polyaniline can be synthesized by adding 0.2 mol of sodium dodecyl sulfate (SDS) to 100 ml of an aqueous solution containing 0.2 mol of aniline hydrochloride, heating and further adding 0.25 mol of ammonium persulfate as a polymerization initiator to carry out oxidative polymerization. Subsequently, acetone or methanol is added to the thus obtained reaction solution, thereby obtaining polyaniline precipitation (see, for example, the publication of Japanese Patent No. 3426637).
The polyaniline obtained as described above is a particle having a diameter of about 10 to 50 nm and has a property of extremely easily cohering, and which makes it difficult to store, hence problematic. Under the circumstance, the polyaniline particle is mixed with polyvinyl butyral and an alcohol-containing solvent, which is then volatilized to prevent the polyaniline particles from cohering.
With this procedure, a solid mixture having a diameter of about 8 mm with polyaniline dispersed in a matrix of polyvinyl butyral is obtained. Consequently, polyaniline can be stored in the form of the above solid mixture without coherence.
However, the solid mixture containing the polyaniline is difficult to crush due to the high hardness and cannot be dispersed in the alcohol-containing solvent when the alcohol-containing solvent is added again and knead, thereby being difficult to use in an anti-corrosive coating composition, hence inconvenient.